Power transmissions require oil or other lubricating materials to carry away thermal energy dissipated by the power transmission components. This is especially true for electromechanical transmissions having an electric motor housed inside the transmission. The lubricating oil originates in an oil reserve and is directed by a pump that distributes the oil centrifugally throughout the transmission. The operating temperatures of the bearing components supporting the planetary gear loads can be of considerable concern. To ensure sufficient lube oil flow to the intended internal components, the transmission design has to be carefully considered to provide sufficient oil flow to components along the entire length of the transmission.
An electro-mechanical transmission is described and commonly assigned U.S. Provisional Ser. No. 60/531,528 entitled “Two-Mode Compound-Split, Hybrid Electro-Mechanical Transmission Having Four Fixed Ratios,” Schmidt et al., filed Dec. 19, 2003 and hereby incorporated by reference in its entirety.